Is your name on the business? That would enable you to get the records from the phone company. Is there online access with a password already set up? If not, and you are on the account, you can set it up and H wouldn't know if he doesn't ever get online.
If you have to check his phone then take a page out of Puppy's book. He learned his W's habits and when she left her phone unattended he got to it and looked through the texts. You should have a digital camera ready to go, then you can photograph the call history and check the numbers later. Plus you want the pics in case you need hard evidence.
If you love somebody, set them free. http://tinyurl.com/2empx2g
